Parse existing NFO for TMDB ID to skip redundant search

Check existing tvshow.nfo for TMDB ID before querying TMDB API.
If found, fetch details directly using cached ID instead of searching.
Reduces API calls and improves performance for already-indexed series.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

docs/NFO_GUIDE.md

@@ -246,6 +246,7 @@ NFO files are created in the anime directory:
     <genre>Action</genre>
     <genre>Sci-Fi & Fantasy</genre>
     <uniqueid type="tmdb">1429</uniqueid>
+    <tmdbid>1429</tmdbid>
     <thumb aspect="poster">https://image.tmdb.org/t/p/w500/...</thumb>
     <fanart>
         <thumb>https://image.tmdb.org/t/p/original/...</thumb>
@@ -253,6 +254,13 @@ NFO files are created in the anime directory:
 </tvshow>
 ```
 
+**Manual TMDB ID Override**: To skip TMDB search and use a specific ID directly, include `<tmdbid>YOUR_ID</tmdbid>` in the NFO. This is useful when:
+- TMDB search fails for your series (e.g., new or obscure anime)
+- You already know the correct TMDB ID
+- You want to avoid rate limiting from repeated searches
+
+Aniworld reads `<tmdbid>` element and `<uniqueid type="tmdb">` first. If found, it uses the ID directly instead of searching.
+
 ### 4.3 Episode NFO Format
 
 ```xml
@@ -629,6 +637,36 @@ Every poster check action is logged:
 4. Check network speed to TMDB servers
 5. Verify disk I/O performance
 
+### 6.7 TMDB Lookup Fails for My Series
+
+**Problem**: TMDB search fails with "No results found" for a valid series.
+
+**Solutions**:
+
+1. **Check if series exists on TMDB**: Visit https://www.themoviedb.org and search for your series
+2. **Use manual ID override**: Add TMDB ID directly to `tvshow.nfo`:
+   ```xml
+   <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+   <tvshow>
+       <title>Your Series Name</title>
+       <tmdbid>12345</tmdbid>
+       <uniqueid type="tmdb">12345</uniqueid>
+   </tvshow>
+   ```
+   Aniworld will use this ID directly instead of searching.
+
+3. **Try alternative titles**: Some anime have different titles (Japanese, romaji, English). If you have access to the folder, rename it to match the TMDB title.
+
+4. **Add to existing NFO**: If `tvshow.nfo` exists but has no TMDB ID, edit it to add:
+   ```xml
+   <tmdbid>YOUR_TMDB_ID</tmdbid>
+   ```
+   Then use the Update endpoint to refresh metadata.
+
+5. **Check for rate limiting**: If many lookups fail at once, you may be hitting TMDB rate limits. Wait and retry later.
+
+6. **Verify API key**: Ensure your TMDB API key is valid and has not exceeded usage limits.
+
 ---
 
 ## 7. Best Practices